Neurotransmitters

Amino acid-derived

Major excitatory /
inhibitory systems

Glutamate system	Agmatine Aspartic acid (aspartate) Glutamic acid (glutamate) Glutathione Glycine GSNO GSSG Kynurenic acid NAA NAAG Proline Serine
GABA system	GABA GABOB GHB
Glycine system	α-Alanine β-Alanine Glycine Hypotaurine Proline Sarcosine Serine Taurine
GHB system	GHB T-HCA (GHC)

Biogenic amines

Monoamines	6-OHM Dopamine Epinephrine (adrenaline) NAS (normelatonin) Norepinephrine (noradrenaline) Serotonin (5-HT)
Trace amines	3-Iodothyronamine N-Methylphenethylamine N-Methyltryptamine m-Octopamine p-Octopamine Phenylethanolamine Phenethylamine Synephrine Tryptamine m-Tyramine p-Tyramine
Others	Histamine

See here instead.

Lipid-derived

Endocannabinoids

See here instead.

Nucleobase-derived

Nucleosides

Adenosine system	ADP AMP ATP

Vitamin-derived

Miscellaneous

Cholinergic system	Acetylcholine

Gasotransmitters	Carbon monoxide (CO) Hydrogen sulfide (H₂S) Nitric oxide (NO)

Candidates	Acetaldehyde Ammonia (NH₃) Carbonyl sulfide (COS) Nitrous oxide (N₂O) Sulfur dioxide (SO₂)

Category